Anorexia vs. Bulimia: Key Differences Explained

People of all ages, racial and ethnic backgrounds, body weights, and sexes can experience eating disorders like anorexia nervosa and bulimia nervosa.¹ The main difference between anorexia and bulimia is that anorexia involves restriction leading to significantly low body weight, while bulimia involves recurrent binge eating followed by behaviors intended to prevent weight gain.^2,3

Both eating disorders can have serious and potentially life-threatening effects on physical and mental health.¹ Learning their differences, recognizing warning signs, and knowing when to seek help can support earlier access to appropriate care.

What Is Anorexia Nervosa?

Anorexia nervosa is an eating disorder that involves severely restricting food or energy intake, which can lead to a body weight that is too low for a person's age, sex, developmental stage, and overall health.²

There are two types of anorexia nervosa:²

• Restricting type: A person does not regularly engage in binge eating or purging behaviors. Weight loss may occur through food restriction, fasting, excessive exercise, or a combination of these behaviors.
• Binge-eating/purging type: A person experiences recurrent episodes of binge eating, purging, or both.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) identifies three main criteria for anorexia nervosa:²

1. Persistent restriction of energy intake, leading to a body weight that is significantly below what is expected for a person's age, sex, and developmental trajectory.
2. An intense fear of gaining weight or becoming overweight, a relentless pursuit of thinness, or ongoing behaviors that interfere with weight gain despite low body weight.
3. A disturbance in how body weight or shape is experienced, which may include distorted body image, difficulty recognizing the seriousness of low body weight, or placing too much importance on weight or shape when evaluating oneself.

Only a qualified healthcare or medical professional can diagnose an eating disorder and determine which type of anorexia a person may be experiencing.

Learn more about the warning signs of anorexia nervosa, or take our 1-minute anorexia assessment.

What Is Bulimia Nervosa?

Bulimia nervosa involves repeated episodes of binge eating followed by behaviors meant to prevent weight gain, known as compensatory behaviors.³ During a binge-eating episode, a person eats an unusually large amount of food within a limited period and feels a loss of control over their eating.³

Compensatory behaviors may include self-induced vomiting, fasting, excessive exercise, or misuse of laxatives, diuretics, diet pills, or other medications.³

The DSM-5 outlines several criteria for bulimia nervosa:³

1. Recurrent episodes of binge eating, involving an unusually large amount of food and a sense of loss of control.
2. Recurrent compensatory behaviors to prevent weight gain, such as vomiting, fasting, excessive exercise, or medication misuse.
3. Binge eating and compensatory behaviors occur at least once a week for three months.
4. Body weight and shape have an excessive influence on self-evaluation and overall self-worth.

These behaviors must also occur outside of exclusive episodes of anorexia nervosa for a diagnosis of bulimia nervosa.³

Learn more about bulimia nervosa symptoms, causes, and treatment, or take our 1-minute bulimia assessment.

How Anorexia Nervosa and Bulimia Nervosa Are Similar

Although anorexia nervosa and bulimia nervosa involve different diagnostic patterns, both may involve intense concerns about food, weight, or body shape and can affect physical health, mental health, relationships, and daily functioning.¹

Eating disorders are mental health conditions, not choices.¹ Their exact causes are not fully understood, but genetic, biological, behavioral, psychological, and social factors may contribute to risk.¹ Common co-occurring disorders can include depression, anxiety, and substance use disorders.¹

Because symptoms between eating disorders and other medical conditions can overlap, professional assessment is necessary for proper diagnosis and treatment than trying to identify a diagnosis based on a single behavior, physical characteristic, or body weight.^4,7

How Clinicians Tell Anorexia Nervosa and Bulimia Nervosa Apart

Clinicians consider the overall pattern of eating habits and weight-control behaviors as well as physical and mental health.^4,7 An evaluation may include:⁴

• Eating patterns and food restriction.
• Binge-eating episodes.
• Purging or other compensatory behaviors.
• Weight history and recent changes.
• Thoughts about food, weight, and body shape.
• Exercise patterns.
• Co-occurring mental health symptoms.
• Possible medical complications.

“Being direct and sensitive when asking about binging or purging related to bulimia is important. There is a delicate line to balance here, and it can be managed with tone, building trust, and appropriate timing. Clinicians can also ask about their recent diet history and exercise patterns. This may not directly or completely uncover behaviors, but it can be a leading indicator of areas where there may be some concerns.” -Silvi Saxena, MBA, MSW, LSW, CCTP, OSW-C

The American Psychiatric Association recommends that laboratory assessments for a possible eating disorder include a complete blood count and comprehensive metabolic panel, including electrolytes, liver enzymes, and kidney function tests.⁴ An electrocardiogram may also be recommended for people with restrictive eating disorders, severe purging behaviors, or medications that can prolong the heart's QTc interval.⁴

Health Risks of Anorexia Nervosa and Bulimia Nervosa

Both anorexia and bulimia can cause serious medical complications and affect multiple body systems.¹

Health Risks of Anorexia Nervosa

Prolonged inadequate nutrition from anorexia can affect nearly every part of the body.¹ Possible complications include:¹

• Persistent fatigue.
• Severe constipation.
• Anemia.
• Low blood pressure.
• Slowed breathing or pulse.
• Muscle weakness or wasting.
• Fertility problems.
• Brain-related complications.
• Heart complications.
• Multiple organ failure.

Suicide is the leading cause of death among people with anorexia and the risk of suicidal thoughts is elevated in those with eating disorders.^1,8 Symptoms related to self-harm or suicide require immediate attention.

Health Risks of Bulimia Nervosa

Repeated binge eating and compensatory behaviors can also affect several body systems.¹ Frequent purging may contribute to:¹

• Chronic throat irritation.
• Swollen salivary glands.
• Tooth enamel erosion and dental problems.
• Acid reflux and other gastrointestinal problems.
• Dehydration.
• Electrolyte imbalances.

Severe dehydration, electrolyte disturbances, malnutrition, or organ dysfunction may require urgent medical care or hospitalization.⁷

Treatment for Anorexia Nervosa and Bulimia Nervosa

Treatment for anorexia nervosa and bulimia nervosa shares many of the same goals, including improving eating patterns, addressing eating-disorder thoughts and behaviors, treating medical complications, and supporting long-term recovery.¹ The American Psychiatric Association recommends coordinated, person-centered care that may involve medical providers, mental health professionals, dietitians, and other clinicians with experience treating eating disorders.⁴

Treatment commonly includes:^1,4

• Medical care and monitoring to identify and manage complications related to inadequate nutrition, binge eating, purging, or other eating-disorder behaviors.
• Nutritional support to help establish consistent, adequate eating patterns and address individual nutritional needs.
• Eating-disorder-focused psychotherapy to address behaviors, thoughts, emotions, and beliefs related to food, eating, weight, and body image.
• Treatment for co-occurring mental health conditions, such as depression or anxiety, when present.
• Family or caregiver involvement, particularly for children, adolescents, and some emerging adults.

The specific treatment plan depends on a person's diagnosis, age, medical stability, eating-disorder behaviors, mental health needs, available support, and treatment preferences.⁴ Although many elements of care overlap, treatment also addresses features specific to each disorder.

“The most promising development I have seen in eating disorder treatment for Anorexia and Bulimia is the increase in adoption of the Health at Every Size Approach. So often, patients living in larger bodies have fallen by the wayside due to the stereotypes of what an eating disorder ‘should look like,’ when eating disorders are, first and foremost, mental illnesses that have a physical impact. By treating the physical impacts of the disorder but not using them to determine the severity of one patient’s condition over another, and incorporating a variety of therapies (such as DBT, ACT, CBT, and family therapy), eating disorders are being treated at all angles.” -Sage Nestler, MSW | Releasing the Phoenix

Considerations for Anorexia Nervosa and Bulimia Nervosa Treatment

Treatment for anorexia nervosa often focuses on restoring adequate nutrition and addressing the effects of malnutrition.⁴ When weight restoration is needed, care may include individualized nutrition and weight-gain goals, along with ongoing medical monitoring.⁴

For bulimia nervosa, treatment commonly focuses on reducing binge-eating episodes and compensatory behaviors while helping patients establish more consistent eating patterns.⁴ Medication may also be part of care. The APA recommends a serotonin reuptake inhibitor, such as fluoxetine, either as part of initial treatment or when psychotherapy alone has not produced an adequate response.⁴

Levels of Care for Eating Disorders

Eating-disorder treatment can occur in the following settings:

• Inpatient treatment
• Partial hospitalization programs (PHPs)
• Intensive outpatient programs (IOPs)
• Standard outpatient programs

A higher level of care may be needed when medical risk, eating-disorder behaviors, psychiatric symptoms, or lack of progress require more intensive support, such as that offered through hospitalization.⁴

Learn more about eating disorder treatment options and how different levels of care work.

What To Do If You Recognize These Signs

You do not need to know exactly what is happening or have a diagnosis before asking for help.⁵ If changes in eating, exercise, weight, or body image are causing distress, affecting your health, or interfering with everyday life, a healthcare provider or eating-disorder specialist can assess your symptoms and recommend appropriate support.^1,7

You also do not need to wait until symptoms become severe. Depending on your needs, support may include medical monitoring, nutrition care, therapy, or specialized eating-disorder treatment.^1,7

“It is important for families of loved ones in eating disorder recovery to be gentle and firm simultaneously. Be gentle in a way that validates one’s feelings, but be firm in not accommodating anxiety around eating. What would that look like? One may say to their loved one, ‘I can understand how you feel, and it is important to follow your therapist’s recommendations and eat to nourish your body.’ Using the word ‘and’ instead of ‘but’ validates both aspects of one’s experience and their long-term goal.” -Jennifer Chicoine MA, LCPC, CCTP | Peaceful Healing Counseling Services

If you are concerned about a loved one or someone you care about, focus on specific changes you have noticed and your concern for their well-being rather than their appearance, weight, or whether they meet the criteria for a particular diagnosis. A compassionate, nonjudgmental approach can make it easier to start the conversation.

For more guidance, see how to help someone with an eating disorder.

Find Eating Disorder Treatment

Anorexia nervosa and bulimia nervosa are different conditions, but both can significantly affect physical health, mental health, and daily life.¹ Treatment can be matched to a person's symptoms, medical needs, age, and circumstances.⁴

If you're ready to explore specialized care or need additional information, you can compare eating disorder treatment centers by location, insurance, level of care, treatment approach, and other factors that matter to you.